天気が悪かったので彼らは泳げなかった。

天気が悪かったので彼らは泳げなかった。

They couldn't swim because of bad weather.

天気(てんき)が悪(わる)かったので彼(かれ)らは泳(およ)げなかった。

Tenki ga warukatta node karera wa oyogenakatta.

天気 (てんき)

weather; the elements; fair weather; fine weather

が (が)

indicates sentence subject (occasionally object); indicates possessive (esp. in literary expressions); but; however; still; and

悪い (わるい)

bad; poor; inferior; evil; sinful; unprofitable; unbeneficial; at fault; to blame; in the wrong; sorry

ので (ので、んで)

that being the case; because of ...; the reason is ....; given that...

彼ら (かれら)

they (usually male); them

は (は)

topic marker particle; indicates contrast with another option (stated or unstated); adds emphasis

Readings: テン、あまつ、あめ、あま-

Meanings: heavens, sky, imperial

Readings: キ、ケ、いき

Meanings: spirit, mind, air, atmosphere, mood

Readings: アク、オ、わる.い、わる-、あ.し、にく.い、 -にく.い、ああ、いずくに、いずくんぞ、にく.む

Meanings: bad, vice, rascal, false, evil, wrong

Readings: ヒ、かれ、かの、か.の

Meanings: he, that, the

Readings: エイ、およ.ぐ

Meaning: swim